import sys

if sys.version_info < (3,):
    def isbasestring(s):
        return isinstance(s, basestring)
    def open_utf8(filename, mode):
        return open(filename, mode)
    def byte_to_str(x):
        return str(ord(x))
    import cStringIO
    def StringIO():
        return cStringIO.StringIO()
    def encode_utf8(x):
        return x
    def decode_utf8(x):
        return x
    def iteritems(d):
        return d.iteritems()
    def itervalues(d):
        return d.itervalues()
    def escape_string(s):
        if isinstance(s, unicode):
            s = s.encode('ascii')
        result = ''
        for c in s:
            if not (32 <= ord(c) < 127) or c in ('\\', '"'):
                result += '\\%03o' % ord(c)
            else:
                result += c
        return result

else:
    def isbasestring(s):
        return isinstance(s, (str, bytes))
    def open_utf8(filename, mode):
        return open(filename, mode, encoding="utf-8")
    def byte_to_str(x):
        return str(x)
    import io
    def StringIO():
        return io.StringIO()
    import codecs
    def encode_utf8(x):
        return codecs.utf_8_encode(x)[0]
    def decode_utf8(x):
        return codecs.utf_8_decode(x)[0]
    def iteritems(d):
        return iter(d.items())
    def itervalues(d):
        return iter(d.values())
    def charcode_to_c_escapes(c):
        rev_result = []
        while c >= 256:
            c, low = (c // 256, c % 256)
            rev_result.append('\\%03o' % low)
        rev_result.append('\\%03o' % c)
        return ''.join(reversed(rev_result))
    def escape_string(s):
        result = ''
        if isinstance(s, str):
            s = s.encode('utf-8')
        for c in s:
            if not(32 <= c < 127) or c in (ord('\\'), ord('"')):
                result += charcode_to_c_escapes(c)
            else:
                result += chr(c)
        return result

